Node management operations 

Use OpsCenter to run operations on nodes in an easy to use, visual way that takes the guesswork out of properly managing nodes in a cluster.

Managing multiple nodes 

Use OpsCenter to run operations (or actions) on nodes in an easy to use, visual way that takes the guesswork out of properly managing nodes in a cluster. Most node management operations can be run on multiple nodes of your choosing (for example, all the nodes in a cluster, all the nodes in a single datacenter, or a handful of problem nodes). The operations run in a rolling fashion and do not continue on to the next node until the previous one has completed successfully. If the operation fails on a node, the entire process stops.

To run an operation on multiple nodes, select those nodes in List View and choose an appropriate action.



Notifications appear when an operation starts and completes. Clicking Show Details takes you to the Activities section.



Managing single nodes 

To run an operation on a single node, click that node from Ring View or List View and choose an action from the Actions menu from the node details view:



Operations details 

View Metrics (single node only)
Redirects you to the Dashboard area of OpsCenter where you can select metrics graphs and configure performance views for the selected node.
View Replication (ring view, single datacenter only)
Shows the replication relationships between the selected node and other nodes in the cluster, based on the selected keyspace.



Start/Stop
Starts or stops the DataStax Enterprise process on the node.
Restart
Restarts the DataStax Enterprise process on the node. If running on multiple nodes, each node is started as soon as the start command for the previous node returns. If you want the operation to wait for thrift to be active on each node before continuing, use the Rolling Restart action.
Cleanup
Removes rows for which the node is no longer responsible. This is usually done after changing the partitioner tokens or the replication options for a cluster.
Compact
Performs a major compaction, which is not a recommended procedure in most DataStax Enterprise clusters.
Flush
Flushes to disk as persistent SSTables the recent writes currently stored in memory (memtables).
Repair
Makes a node consistent with its replicas by doing an in-memory comparison of all the rows of a table and resolving any discrepancies between replicas by updating outdated rows with the current data.
Perform GC
Forces the Java Virtual Machine (JVM) on the selected node to perform a garbage collection (GC).
Decommission (single node only)
Removes a node from the cluster and streams its data to neighboring replicas.
Drain (single node only)
Causes the recent writes currently stored in memory (memtables) to be flushed to disk as persistent SSTables and then makes the node read-only. The node stops accepting new writes. Draining a node is usually done when upgrading a node.
Move (single node only)
Changes the partitioner token assignment for the node, thus changing the range of data that the node is responsible for. Not enabled if vnodes are enabled.